I totally understand where you are coming from. Now, I am going to give you another view.
There have been times when I get back a sheltie for a visit, and grooming, and the dog looks beautiful on top. Underneath, the dog is packed with mats. Before any of you scream, "That's not me, with my dog", sometimes people don't realize the amount of matting that can get inside the back legs and under the belly. Heck, there can be huge mat balls behind the ears, and owners pet their dogs on the head all the time.They can't feel them? How often are the owners underneath the back end? I have been totally shocked at what I find. The owners are very sincere in their love and care of the dog, but just don't realize they have to brush and comb out periodically.
Of course, I have instructed this, over and over.
I had a dog recently that the wads of mats between his back legs and behind his ears were huge. I just took the scissors and wacked them off. I'm sure his bum looked naked to his owners, but that was my only option.
So, I now somewhat understand the groomers dilemma